1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> 4 */ 5 6 #include <unistd.h> 7 #include <asm/orc_types.h> 8 #include <objtool/objtool.h> 9 #include <objtool/warn.h> 10 #include <objtool/endianness.h> 11 12 static const char *reg_name(unsigned int reg) 13 { 14 switch (reg) { 15 case ORC_REG_PREV_SP: 16 return "prevsp"; 17 case ORC_REG_DX: 18 return "dx"; 19 case ORC_REG_DI: 20 return "di"; 21 case ORC_REG_BP: 22 return "bp"; 23 case ORC_REG_SP: 24 return "sp"; 25 case ORC_REG_R10: 26 return "r10"; 27 case ORC_REG_R13: 28 return "r13"; 29 case ORC_REG_BP_INDIRECT: 30 return "bp(ind)"; 31 case ORC_REG_SP_INDIRECT: 32 return "sp(ind)"; 33 default: 34 return "?"; 35 } 36 } 37 38 static const char *orc_type_name(unsigned int type) 39 { 40 switch (type) { 41 case ORC_TYPE_UNDEFINED: 42 return "(und)"; 43 case ORC_TYPE_END_OF_STACK: 44 return "end"; 45 case ORC_TYPE_CALL: 46 return "call"; 47 case ORC_TYPE_REGS: 48 return "regs"; 49 case ORC_TYPE_REGS_PARTIAL: 50 return "regs (partial)"; 51 default: 52 return "?"; 53 } 54 } 55 56 static void print_reg(unsigned int reg, int offset) 57 { 58 if (reg == ORC_REG_BP_INDIRECT) 59 printf("(bp%+d)", offset); 60 else if (reg == ORC_REG_SP_INDIRECT) 61 printf("(sp)%+d", offset); 62 else if (reg == ORC_REG_UNDEFINED) 63 printf("(und)"); 64 else 65 printf("%s%+d", reg_name(reg), offset); 66 } 67 68 int orc_dump(const char *_objname) 69 { 70 int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0; 71 struct orc_entry *orc = NULL; 72 char *name; 73 size_t nr_sections; 74 Elf64_Addr orc_ip_addr = 0; 75 size_t shstrtab_idx, strtab_idx = 0; 76 Elf *elf; 77 Elf_Scn *scn; 78 GElf_Shdr sh; 79 GElf_Rela rela; 80 GElf_Sym sym; 81 Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL; 82 struct elf dummy_elf = {}; 83 84 85 objname = _objname; 86 87 elf_version(EV_CURRENT); 88 89 fd = open(objname, O_RDONLY); 90 if (fd == -1) { 91 perror("open"); 92 return -1; 93 } 94 95 elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); 96 if (!elf) { 97 WARN_ELF("elf_begin"); 98 return -1; 99 } 100 101 if (!elf64_getehdr(elf)) { 102 WARN_ELF("elf64_getehdr"); 103 return -1; 104 } 105 memcpy(&dummy_elf.ehdr, elf64_getehdr(elf), sizeof(dummy_elf.ehdr)); 106 107 if (elf_getshdrnum(elf, &nr_sections)) { 108 WARN_ELF("elf_getshdrnum"); 109 return -1; 110 } 111 112 if (elf_getshdrstrndx(elf, &shstrtab_idx)) { 113 WARN_ELF("elf_getshdrstrndx"); 114 return -1; 115 } 116 117 for (i = 0; i < nr_sections; i++) { 118 scn = elf_getscn(elf, i); 119 if (!scn) { 120 WARN_ELF("elf_getscn"); 121 return -1; 122 } 123 124 if (!gelf_getshdr(scn, &sh)) { 125 WARN_ELF("gelf_getshdr"); 126 return -1; 127 } 128 129 name = elf_strptr(elf, shstrtab_idx, sh.sh_name); 130 if (!name) { 131 WARN_ELF("elf_strptr"); 132 return -1; 133 } 134 135 data = elf_getdata(scn, NULL); 136 if (!data) { 137 WARN_ELF("elf_getdata"); 138 return -1; 139 } 140 141 if (!strcmp(name, ".symtab")) { 142 symtab = data; 143 } else if (!strcmp(name, ".strtab")) { 144 strtab_idx = i; 145 } else if (!strcmp(name, ".orc_unwind")) { 146 orc = data->d_buf; 147 orc_size = sh.sh_size; 148 } else if (!strcmp(name, ".orc_unwind_ip")) { 149 orc_ip = data->d_buf; 150 orc_ip_addr = sh.sh_addr; 151 } else if (!strcmp(name, ".rela.orc_unwind_ip")) { 152 rela_orc_ip = data; 153 } 154 } 155 156 if (!symtab || !strtab_idx || !orc || !orc_ip) 157 return 0; 158 159 if (orc_size % sizeof(*orc) != 0) { 160 WARN("bad .orc_unwind section size"); 161 return -1; 162 } 163 164 nr_entries = orc_size / sizeof(*orc); 165 for (i = 0; i < nr_entries; i++) { 166 if (rela_orc_ip) { 167 if (!gelf_getrela(rela_orc_ip, i, &rela)) { 168 WARN_ELF("gelf_getrela"); 169 return -1; 170 } 171 172 if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) { 173 WARN_ELF("gelf_getsym"); 174 return -1; 175 } 176 177 if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) { 178 scn = elf_getscn(elf, sym.st_shndx); 179 if (!scn) { 180 WARN_ELF("elf_getscn"); 181 return -1; 182 } 183 184 if (!gelf_getshdr(scn, &sh)) { 185 WARN_ELF("gelf_getshdr"); 186 return -1; 187 } 188 189 name = elf_strptr(elf, shstrtab_idx, sh.sh_name); 190 if (!name) { 191 WARN_ELF("elf_strptr"); 192 return -1; 193 } 194 } else { 195 name = elf_strptr(elf, strtab_idx, sym.st_name); 196 if (!name) { 197 WARN_ELF("elf_strptr"); 198 return -1; 199 } 200 } 201 202 printf("%s+%llx:", name, (unsigned long long)rela.r_addend); 203 204 } else { 205 printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i])); 206 } 207 208 printf("type:%s", orc_type_name(orc[i].type)); 209 210 printf(" sp:"); 211 212 print_reg(orc[i].sp_reg, bswap_if_needed(&dummy_elf, orc[i].sp_offset)); 213 214 printf(" bp:"); 215 216 print_reg(orc[i].bp_reg, bswap_if_needed(&dummy_elf, orc[i].bp_offset)); 217 218 printf(" signal:%d\n", orc[i].signal); 219 } 220 221 elf_end(elf); 222 close(fd); 223 224 return 0; 225 } 226